Comparison of NDE techniques for assessing mechanical properties of unjointed and finger-jointed lumber

Abstract Non-destructive evaluation (NDE) methods are common for grading structural lumber with static bending as the traditional NDE method for strength. More recently, longitudinal and transverse vibration techniques have also been proposed for grading lumber. In this study, unjointed and finger-jointed sawn lumber has been evaluated by these traditional and relatively new NDE methods. In total, 188 pieces of 38 mm×89 mm black spruce lumber were tested. Of these, 40 were unjointed, 47 had 2–3 finger joints, and 101 had 5–7 finger joints. The main objective was to evaluate the reliability of the various NDE techniques in predicting the bending stiffness and tensile strength of finger-jointed lumber with different number of finger joints. Results show that all NDE methods provide stiffness values of unjointed and finger-jointed lumber that correlate well with laboratory measured static bending stiffness with R2 values ranging from 0.76 to 0.97. Moreover, lumber with finger joints has lower bending stiffness than unjointed lumber. Based on the correlation coefficients, there is no evidence that finger joints affect the precision of the strength prediction by NDE methods.

Download Full-text

A Non-Destructive Evaluation Method: Measuring the Fixed Strength of Spot Welded Joint Points by Surface Electric Resistivity

ASME 2010 Pressure Vessels and Piping Conference: Volume 5 ◽

10.1115/pvp2010-25235 ◽

2010 ◽

Author(s):

Akira Shimamoto ◽

Keitaro Yamashita ◽

Hirofumi Inoue ◽

Sung-mo Yang ◽

Masahiro Iwata ◽

...

Keyword(s):

Tensile Strength ◽

Spot Welding ◽

Evaluation Method ◽

Welded Joint ◽

Electric Resistivity ◽

Electric Resistance ◽

Non Destructive Evaluation ◽

Nugget Diameter ◽

Zinc Plating ◽

Non Destructive

Destructive tests are generally applied for evaluating fixed strength of spot welding nuggets on zinc plating steel, which is swidely used as the primary automobile structural material. Destructive tests, however, are expensive and time consuming. This paper discusses a non-destructive method for evaluating of welded joints fixed strength by utilizing surface electric resistance. A nugget tester has developed by authors for this purpose. The non-destructive method focuses on surface electric resistance decreasing rate; α, and effect of the corona bond. Nugget diameter is estimated by RQuota calculated from variation of resistance and constant representing the area of the corona bond. Since maximum tensile strength is correlated with the nugget diameter, it is inferred from the estimated nugget diameter.

Download Full-text

Non-destructive evaluation of mechanical properties of poly (vinyl) alcohol-hydroxyapatite nanocomposites

Journal of Materials Science Materials in Medicine ◽

10.1007/s10856-009-3959-y ◽

2010 ◽

Vol 21 (4) ◽

pp. 1099-1102 ◽

Cited By ~ 1

Author(s):

Suprabha Nayar ◽

Sharmistha P. Sagar ◽

Avijit Guha

Keyword(s):

Mechanical Properties ◽

Vinyl Alcohol ◽

Poly Vinyl Alcohol ◽

Non Destructive Evaluation ◽

Non Destructive

Download Full-text

Quantitative Relationships between Mechanical Properties and Microstructure of Ti17 Alloy after Thermomechanical Treatment

Metals ◽

10.3390/met10010067 ◽

2020 ◽

Vol 10 (1) ◽

pp. 67

Author(s):

Yan Han ◽

Fei Zhao ◽

Yuan Liu ◽

Chaowen Huang

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Impact Toughness ◽

Tensile Properties ◽

Aging Temperature ◽

Correlation Coefficients ◽

Opposite Trend ◽

Coarsening Behavior ◽

Reduction Of Area ◽

The Impact

In this paper, the relationships between the thermomechanical treatments (TMT), the microstructural evolution the mechanical properties of Ti17 alloy were investigated. The results indicate the coarsening behavior of lamellar α was sensitive to the aging temperature during the process of TMT. The thickness of lamellar α changed from 0.19 to 0.38 μm with an increase in the aging temperature. Moreover, both tensile properties and impact toughness vary with the thickness of lamellar α. The tensile strength increases with the increase of the thickness of lamellar α the plasticity and impact toughness the opposite trend. The quantitative investigations found that there is a linear relationship between the tensile properties and the thickness of lamellar α the tensile properties could be adjusted in the range of 1191~1062 MPa and 1163~1039 MPa to obtain ultimate tensile strength and yield strength as well as 11~16% elongation and 23~33% reduction of area by varying the thickness of lamellar α. Meanwhile, the impact toughness could be adjusted in the range of 46 ~53 J/cm2. The high correlation coefficients imply that the linear equation is reliable to describe the relationships between the mechanical properties and the thickness of lamellar α for Ti17 alloy.

Download Full-text

Analysis of the Mechanical Properties of TC4-6061 Composite Plate Based on Classical Laminate Theory

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.724.12 ◽

2015 ◽

Vol 724 ◽

pp. 12-16 ◽

Cited By ~ 2

Author(s):

Qiang Wang ◽

Li Lin Liang ◽

Chao Nan Peng

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Composite Plate ◽

Bending Strength ◽

Alloy Layer ◽

Bending Stiffness ◽

Strength Increase ◽

Specific Strength ◽

Tensile Stiffness ◽

Laminate Theory

The calculation formula for the mechanical properties of TC4-6061 composite plate was deduced based on classical laminate theory. The stiffness, the strength, the specific stiffness and the specific strength for the plates was calculated by using the formula. The results show that with increasing of the relative thickness of titanium alloy layer, the tensile stiffness, the bending stiffness, the tensile strength and the bending strength increase rapidly, the tensile stiffness and tensile strength change little, the bending stiffness and specific bending strength first increase and then decrease.

Download Full-text

Non-destructive evaluation of the mechanical properties of pharmaceutical solid dosage forms with teraHertz imaging

2007 Joint 32nd International Conference on Infrared and Millimeter Waves and the 15th International Conference on Terahertz Electronics ◽

10.1109/icimw.2007.4516648 ◽

2007 ◽

Author(s):

R.S. Hutton

Keyword(s):

Mechanical Properties ◽

Terahertz Imaging ◽

Dosage Forms ◽

Solid Dosage Forms ◽

Solid Dosage ◽

Non Destructive Evaluation ◽

Non Destructive

Download Full-text

Multivariate non-destructive evaluation for tensile strength of steel based on neural network

Insight - Non-Destructive Testing and Condition Monitoring ◽

10.1784/insi.2021.63.7.427 ◽

2021 ◽

Vol 63 (7) ◽

pp. 427-435

Author(s):

Junyang Tan ◽

Dan Xia ◽

Shiyun Dong ◽

Honghao Zhu ◽

Binshi Xu

Keyword(s):

Tensile Strength ◽

Magnetic Hysteresis ◽

Barkhausen Noise ◽

Non Destructive Testing ◽

Magnetic Barkhausen Noise ◽

Testing Methods ◽

Destructive Testing ◽

Ultrasonic Signals ◽

Non Destructive Evaluation ◽

Non Destructive

Tensile strength (TS) is an important mechanical property of a material. The conventional mechanical measurement method destroys the object under investigation; hence, the non-destructive evaluation of tensile strength of materials has become a research hotspot in recent years. Currently, there are some accuracy problems associated with evaluating the tensile strength of materials on the basis of single non-destructive testing (NDT) methods such as ultrasonic or electromagnetic methods. In this study, 45 steel is used as an example to study various non-destructive testing methods. First, seven different heat treatment systems are used to prepare standard specimens with different tensile strengths, which are measured by tensile tests. Second, non-destructive testing signals for each specimen are obtained as ultrasonic signals, magnetic Barkhausen noise and magnetic hysteresis signals, and the characteristic parameters of the signals are extracted. Then, single-parameter non-destructive evaluation (SNE) models of tensile strength with three different non-destructive testing methods are developed. Furthermore, a multivariate non-destructive evaluation (MNE) method based on ultrasonic signals, magnetic Barkhausen noise and magnetic hysteresis is proposed to improve the accuracy of the tensile strength measurements obtained from non-destructive testing. A deep residual network (ResNet) is used to combine the features of the three non-destructive testing parameters and an MNE model of tensile strength is developed. Moreover, a data pretreatment method based on the fuzzy mapping relationship is applied to train the MNE model successfully and enhance the stability, accuracy and reliability of the obtained results. Finally, the accuracies of the above four tensile strength evaluation models are confirmed by verification using the specimens. The results show that the MNE model has higher accuracy than the SNE models.

Download Full-text

Correlation of mechanical properties with non-destructive evaluation measurements in AlLi alloys

Materials Science and Engineering A ◽

10.1016/0921-5093(89)90518-2 ◽

1989 ◽

Vol 119 ◽

pp. 7-15 ◽

Cited By ~ 6

Author(s):

L.J.H. Brasche ◽

D.J. Bracci ◽

D.C. Jiles ◽

O. Buck

Keyword(s):

Mechanical Properties ◽

Non Destructive Evaluation ◽

Non Destructive

Download Full-text

Non-Destructive Evaluation of Mechanical Properties of Magnetic Materials

MRS Proceedings ◽

10.1557/proc-591-157 ◽

1999 ◽

Vol 591 ◽

Cited By ~ 2

Author(s):

Kevin P. Kankolenski ◽

Susan Z. Hua ◽

David X. Yang ◽

G. E. Hicho ◽

L. J. Swartzendruber ◽

...

Keyword(s):

Mechanical Properties ◽

Plastic Deformation ◽

Domain Walls ◽

Tensile Axis ◽

Hysteresis Loops ◽

Strain Curve ◽

Low Carbon ◽

Barkhausen Effect ◽

Non Destructive Evaluation ◽

Non Destructive

ABSTRACTA magnetic-based non-destructive evaluation (NDE) method, which employs Barkhausen effect and measurement of the hysteresis loops, is used to correlate the magnetic and mechanical properties of ultra low carbon (ULC) steel. In particular, the NDE method was used to detect small deviations from linearity that occur in the stress-strain curve well below the 0.2% offset strain, and which generally defines the yield point in materials. Results show that three parameters: jumpsum and jumpsum rate (derived from the Barkhausen spectrum), and the relative permeability (derived from the B-H loops) varies sensitively with small permanent strains, and can be related to the plastic deformation in ULC steels. Investigation of micromagnetic structure revealed that plastic deformation leaves a residual stress state in the samples; the associated magneto-elastic energy makes the favorable easy axis of magnetization in a given grain to be the one that lies closest to the tensile axis. The consequence of this realignment of domains is that wall motion becomes intergranular in nature (as opposed to intragranular in unstrained samples). As a result, the more complex grain boundaries instead of dislocations, become the dominant pinning sites for domain walls. These observations provide a microscopic interpretation of the observed changes in the measured magnetic properties.

Download Full-text